The growth in the number of available media channels and improved reception due to digital broadcasts has driven consumers to look beyond normal television antennas and cable systems. Digital signals broadcast from satellites are capable of providing hundreds of video, audio and data channels to users without the constraint of land line connections. The programming is distributed by a constellation of satellites parked in geostationary orbits at 22,300 miles above the earth. These broadcasts from orbit allow users to receive the broadcasts in many areas; such as mountainous regions or desolate areas, where earth-based transmitters or cable infrastructure traditionally are unable to reach.
A satellite can only broadcast a finite amount of data simultaneously. Therefore, it is sometimes or often necessary for satellite programming providers, for example DISH Network and DirecTV in the United States, to spread their programming across multiple satellites located at different positions or slots in the sky. Thus, for a customer to receive their full compliment of programming, their satellite antenna equipment must aim, lock onto and switch between two or more satellite positions (e.g. 110 degrees, 119 degrees, etc.) depending on which television channel the user has selected via their STB.
For house-mounted antenna systems, a single dish with multiple feed horns can be adjusted in elevation, azimuth and skew so that the data being broadcast from multiple satellite locations can be received simultaneously. Alternatively, two or more dishes may be used. In either case, once the dish is properly aimed and secured, it is not necessary to re-adjust because the house does not move. Often a trained technician is hired to perform the setup and aiming tasks because it must be ensured that the antenna(s) are accurately aimed and oriented at all of the correct satellites corresponding to the programming package to which the user has subscribed. However, providing a solution for mobile environments is a far more complex endeavor.
When a broadcast satellite signal is received by a satellite antenna, an output signal is relayed to a STB. The STB (also referred to as an integrated receiver decoder or IRD) then decodes the audio and video signals, and outputs the decoded signals as regular audio and television signals to be displayed on a television set and played by an audio system. The STB includes certain components, such as microprocessors with corresponding programming code, to determine which satellite is necessary to correspond to the channel selected by the user. The STB also contains electrical components and associated programming to decode the satellite identification information broadcast by each compatible satellite. One common method is referred to as Digital Video Broadcast (DVB) and can be decoded by a DVB circuit board disposed within the STB, which may be integrated or a separate component. Then, using a communications protocol called DiSEqC, the STB can communicate with the individual signal converters (low noise block converters (LNBs)) of the satellite antenna(s) to selectively turn them on and off as required to receive the correct feed corresponding to the desired satellite position as determined by the STB based upon the channel selected by the user.
The positioning of the satellite signal receiving antenna becomes problematic when it is configured as a mobile antenna, such as for vehicle mounting or for portable hand carrying. Mountable satellite antennas may, for example, attach to a bus, boat, motor home, trailer, commercial vehicle, van, camper, trailer or other mobile unit. When such configuration of satellite communication systems are moved to a new location, the elevation and azimuth angles (orientations) of the antenna must be adjusted to align the antenna with the selected satellite. Determining satellite location is especially problematic to the user who may be in a new location every night (or throughout the day). For example, many buses and recreational vehicles have their satellite antenna systems installed on the roof of the vehicle. When they park at night they may have to first position the antenna to an operating position and then adjust elevation and azimuth position to locate the desired satellite.
Due to packaging and cost requirements, most conventional mobile/portable satellite TV antennas can only aim at one satellite position at a time. This allows the systems to be enclosed, made less expensive and packaged smaller than they otherwise would need to be because dish size can be reduced and skew does not need to be adjusted compared to antenna systems like those mounted to the roof of a house that point at multiple satellite positions simultaneously.
Conventional mobile/portable antennas, such as those disclosed in U.S. Pat. Nos. 7,595,764 and 6,538,612, both of which are hereby incorporated by reference in their entirety, thus must be able to change elevation and azimuth so that they are aimed at the correct satellite position; the one that corresponds to the channel the user selected on the STB.
Conventional mobile/portable satellite antennas operate independent of the STB to which they are connected. For example, these devices typically include an onboard DVB board as part of the antenna control system so that the mobile/portable antenna can positively determine the identification of which satellite it is locked onto or needs to switch to. Use of such on-board DVB decoders greatly speeds up the searching process compared to a blind search methodology. However, the inclusion of the redundant DVB hardware and software adds cost, complexity and weight to the mobile satellite antenna. It is also an additional component that could fail. Thus, there is a need to provide for a system, method and device that reduces cost, weight and complexity of the conventional mobile or portable satellite antenna system, and improves reliability, without removing the ability to efficiently operate automatically.